Any planned mating should only take place after full consideration of many factors which the KC have highlighted at https://www.thekennelclub.org.uk/health/for-breeders/breeders-and-coronavirus-covid-19-faqs/

During the current lockdown, which as yet has no certainty over end date, there are additional factors which breeder and purchaser should consider, not least how to maintain social distancing whilst providing appropriate puppy socialisation, handover of puppies, training and ongoing support. In some cases it will be more appropriate to defer the mating, however if the mating has taken place or will take place during lockdown then please consider how you will work within government guidelines for your own health and for the wellbeing of the dogs.
The full guidance on complying with these measures is available on the GOV.UK website: